/* 
 *  Copyright 2012 CodeMagi, Inc.
 * 
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package com.codemagi.servlets.validation;

import com.codemagi.servlets.AppException;
import com.codemagi.util.StringUtils;
import javax.servlet.http.HttpServletRequest;


/**
 * Validate that an input String is less than a certain length
 */
public class StringLengthValidator implements IValidator {

    /** 
     * Error Message to return if the param fails validation. 
     * Use %s to include the max field length.
     */
    private String errorMessage = "Invalid field length. The maximum length for this field is %s ";
    
    private Integer maxLength;

    public StringLengthValidator(Integer maxLength) {
	this.maxLength    = maxLength;
    }

    public StringLengthValidator(Integer maxLength, String errorMessage) {
	this.maxLength    = maxLength;
	this.errorMessage = errorMessage;
    }

    public Object validate(Object obj, HttpServletRequest request) throws AppException {
	if (obj != null && obj instanceof String) {

	    String output = (String)obj;
	    
	    output = StringUtils.trim(output);

	    if ( output.length() > maxLength ) throw new AppException( String.format(errorMessage, maxLength) );

	    return output;
	}

	return obj;
    }

}
